onsemi DM74ALS175N

Overview

DM74ALS175N from Fairchild Semiconductor is a quad D-type flip-flop with asynchronous clear, implemented in advanced oxide-isolated ion-implanted Schottky TTL. It features complementary Q and Q̅ outputs per stage, 50 MHz maximum clock frequency, 10 ns setup time, and operates at 4.5–5.5 V supply across 0°C to +70°C. Used in synchronous logic control, register file staging, and data latching in industrial control systems.

For engineers reviewing the DM74ALS175N datasheet, pinout, applications, or equivalent options, key selection criteria include guaranteed switching performance over full temperature and V_CC range, complementary output capability per flip-flop, and PDIP-16 packaging for through-hole prototyping and legacy board compatibility.

Technical Context

This device implements four independent positive-edge-triggered D-type flip-flops sharing a common asynchronous active-low CLEAR input and a single clock input. Each stage provides true (Q) and complement (Q̅) outputs - a distinguishing feature versus the hex DM74ALS174 variant. Clock triggering is voltage-level sensitive, not edge-slope dependent.

Designed for TTL-compatible interfacing, it guarantees t_PLH/t_PHL propagation delays of 3–15 ns (clock-to-Q) and 5–23 ns (clear-to-Q), with I_OL = 8 mA and I_OH = −0.4 mA drive strength under recommended operating conditions.

Key Specifications

Pinout & Package

DM74ALS175N is housed in a 16-lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300" wide, with through-hole mounting and industry-standard lead pitch (0.100"). Thermal resistance θ_JA = 77.9°C/W.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar quad D-type flip-flop with clear applications.

Compared with SN74ALS175N and DM74LS175N, the DM74ALS175N delivers optimal balance of speed (50 MHz), power efficiency (14 mA ICC), and legacy PDIP compatibility - making it preferred for mid-speed industrial control upgrades where drop-in replacement of LS parts is required without PCB redesign.

Availability

DM74ALS175N is available at Aetrix Electronics and suitable for industrial control systems, legacy test equipment refurbishment, telecom line card maintenance, and avionics panel retrofits requiring stable component supply and long-term obsolescence management.

Supply support for DM74ALS175N includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Fairchild Semiconductor was a U.S.-based designer and manufacturer of analog and mixed-signal ICs, acquired by ON Semiconductor in 2016. Known for high-reliability TTL, MOS, and power products.

The DM74ALS175N belongs to Fairchild's Advanced Low-Power Schottky (ALS) TTL logic family, engineered for speed-power optimization in industrial and instrumentation applications where LS TTL was insufficient but AS TTL too power-hungry.

FAQ

What is the maximum clock frequency supported by the DM74ALS175N?

The DM74ALS175N supports a maximum clock frequency of 50 MHz under recommended operating conditions (V_CC = 4.5–5.5 V, T_A = 0–70°C, R_L = 500 Ω). This value is guaranteed in the Switching Characteristics table and reflects worst-case timing across temperature and voltage. The DM74ALS175N achieves this while maintaining 10 ns setup time and sub-15 ns clock-to-Q propagation delay - critical for synchronizing multi-stage logic in industrial controllers.

Does the DM74ALS175N provide both Q and Q̅ outputs for each flip-flop?

Yes, the DM74ALS175N provides complementary true (Q) and inverted (Q̅) outputs for all four internal D-type flip-flops - a key distinction from the DM74ALS174 hex variant. This is confirmed in the General Description, Function Table (Note 1), and Logic Diagram. The DM74ALS175N's pinout allocates dedicated pins for each Q and Q̅ pair, enabling direct connection to differential receivers or LED drivers without external inverters.

What is the function of Pin 15 (CLR̅) on the DM74ALS175N?

Pin 15 (CLR̅) is the active-low asynchronous clear input shared across all four flip-flops in the DM74ALS175N. When pulled LOW, it forces all Q outputs to LOW immediately - independent of clock state or data inputs. This function is documented in the Function Table and Logic Diagram. The DM74ALS175N uses CLR̅ for system-level reset, power-on initialization, and fault recovery in applications like PLCs and test equipment where deterministic register clearing is required.

Is the DM74ALS175N pin-compatible with the standard 74LS175?

Yes, the DM74ALS175N is pin- and function-compatible with the 74LS175 and other LS-family quad D-type flip-flops. This is explicitly stated in the Features section ("Pin and functional compatible with LS family counterpart") and confirmed by identical pin numbering, logic diagram structure, and function table behavior. The DM74ALS175N can replace 74LS175 in existing designs to improve speed (50 MHz vs. 30 MHz) and reduce power consumption without PCB changes.

What package type is used for the DM74ALS175N?

The DM74ALS175N uses a 16-lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300" wide, designated Package Number N16E. This through-hole package is specified in the Ordering Code table and Physical Dimensions section. Its 0.100" lead pitch and standard footprint make the DM74ALS175N suitable for prototyping, repair, and legacy board assembly where surface-mount variants (e.g., DM74ALS175M) are incompatible.